Malaria is a life-threatening parasitic disease transmitted by
mosquitoes. It was once thought that the disease came from fetid
marshes, hence the name mal aria, ((bad air). In 1880, scientists
discovered the real cause of malaria a one-cell parasite called
plasmodium. Later they discovered that the parasite is transmitted
from person to person through the bite of a female Anopheles
mosquito, which requires blood to nurture her eggs.

Today approximately 40% of the world's population mostly
those living in the world's poorest countries is at risk of malaria.
The disease was once more widespread but it was successfully
eliminated from many countries with temperate climates during
the mid 20th century. Today malaria is found throughout the
tropical and sub-tropical regions of the world and causes more than
300 million acute illnesses and at least one million deaths annually.

Ninety per cent of deaths due to malaria occur in Africa south
of the Sahara mostly among young children. Malaria kills an
African child every 30 seconds. Many children who survive an
episode of severe malaria may suffer from learning impairments
or brain damage. Pregnant women and their unborn children are
also particularly vulnerable to malaria, which is a major cause of
perinatal mortality, low birth weight and maternal anaemia.

There are four types of human malaria Plasmodium vivax, P. malariae, P. ovale and P. falciparum. P. vivax and P. falciparum
are the most common and falciparum the most deadly type of
malaria infection. Plasmodium falciparum malaria is most
common in Africa, south of the Sahara, accounting in large part
for the extremely high mortality in this region. There are also
worrying indications of the spread of P. falciparum malaria into
new regions of the world and its reappearance in areas where it
had been eliminated.

The malaria parasite enters the human host when an infected
Anopheles mosquito takes a blood meal. Inside the human host, the parasite undergoes a series of changes as part of its complex
life-cycle. Its various stages allow plasmodia to evade the
immune system, infect the liver and red blood cells, and finally
develop into a form that is able to infect a mosquito again when
it bites an infected person. Inside the mosquito, the parasite
matures until it reaches the sexual stage where it can again
infect a human host when the mosquito takes her next blood
meal, 10 to 14 or more days later.

Malaria symptoms appear about 9 to 14 days after the
infectious mosquito bite, although this varies with different
plasmodium species. Typically, malaria produces fever, headache,
vomiting and other flu-like symptoms. If drugs are not available
for treatment or the parasites are resistant to them, the infection
can progress rapidly to become life-threatening. Malaria can kill by
infecting and destroying red blood cells (anaemia) and by clogging
the capillaries that carry blood to the brain (cerebral malaria) or
other vital organs.

Malaria, together with HIV/AIDS and TB, is one of the major
public health challenges undermining development in the
poorest countries in the world.

Malaria parasites are developing unacceptable levels of
resistance to one drug after another and many insecticides are no
longer useful against mosquitoes transmitting the disease. Years
of vaccine research have produced few hopeful candidates and
although scientists are redoubling the search, an effective vaccine
is at best years away.

Science still has no magic bullet for malaria and many doubt
that such a single solution will ever exist. Nevertheless, effective
low-cost strategies are available for its treatment, prevention and control and the Roll Back Malaria global partnership is
vigorously promoting them in Africa and other malaria-endemic
regions of the world. Mosquito nets treated with insecticide
reduce malaria transmission and child deaths. Prevention of
malaria in pregnant women, through measures such as
Intermittent Preventive Treatment and the use of insecticide-treated nets (ITNs), results in improvement in maternal health,
infant health and survival. Prompt access to treatment with
effective up-to-date medicines, such as artemisinin-based
combination therapies (ACTs), saves lives. If countries can apply
these and other measures on a wide scale and monitor them,
then the burden of malaria will be significantly reduced.

Roll Back Malaria is a global partnership initiated by WHO, UNDP, UNICEF and the World Bank in 1998. It seeks to work with governments, other development agencies, NGOs, and private sector companies to reduce the human and socio-economic costs of malaria.